Subjects must not have clinically significant cardiac, pulmonary, thyroid, kidney or neurologic impairment, hemostasis disorder, or significant medical condition that would, in the opinion of the principal investigator, affect patient safety and/or compliance. In addition, subjects with the following conditions are specifically excluded: autoimmune disease, inflammatory bowel disease, psoriasis, optic neuritis, congestive heart failure, active ischemic heart disease, uncontrolled diabetes mellitus, moderate or severe hemophilia ( less than or equal to 5% of normal factor VIII levels), seizure disorder, uncontrolled hypothyroidism, cirrhosis and a prior medical history of transplantation. If an investigator has any reservations about the safety of enrolling a particular subject, he/she should consult with the medical monitor prior to screening the subject.